Not Compulsory or Obligatory
This page is the CodyCross answer for the clue below from Extraordinary Creatures, Group 1595, Puzzle 2 (Erymanthian Boar).
Question is: Not Compulsory or Obligatory
and the answer is: VOLUNTARY
Word Meaning:
VOLUNTARY — Done, given, or acting of one's own free will.
Definitions from Wiktionary.